Evaluating Degrees of “Softness” in Therapeutic Systems of Knitted Wearable Technology with Brain Injury Survivors

Abstract

Wearable energy harvesting methods have been increasingly researched over the past decade. Due to demands for finding suitable ways of powering wearable devices suited to garment contexts, yarn-based “components” gather increasing interest. However, the focus of textile properties of energy harvesting components often place emphasis on functional performance and limited elements concerning wearability; using terms such as “flexible”, “breathable” and “wearable”. Rarely, is there consideration for degrees of “comfort”, and “softness”. Yet, if such methods are to become integrated into wearable garments and worn on a daily basis, or even in niche contexts, the tactile experience requires attention. To address this, the following research details an exploration of softness of a polyvinylidene fluoride (PVDF) yarn-based energy harvesting method, amongst brain injury survivors where degrees of sensitivity can vary to extremes; accruing either reduced or heightened levels of sensitivity as a result of stroke, for example. Levels of softness have been defined and quantified from earlier samples responded to by stroke survivors. This has been formed into a chart and used in reference within the development process to refine and detail the methods used to improve the quality of softness in the process of knitting. In contexts, such as the knit lab, participant presence can be limited, yet feedback, especially on subjective matters such as softness, is critical to the development process. The method presented of grading softness in accordance with previous samples is seen to aid the researcher to analyse samples made in situ, within an iterative process of development. The paper focuses on providing conversations around technical data within the knit process to deliver soft and wearable energy harvesting textiles. This forms a part of a wider body of PhD research that explores the use of piezoelectric theory as a technological tool for recovery of upper limb deficits for stroke survivors.